Switch mechanism



May 31 9 19270 G. s. JENMNG SWITCH MECHANISM Filed Aug. 18, 1921 2 Sheets-Sheet 1 Fig.

INVENTOR Oliver 5. Jenni/19a ATTORNEY May 319119270 153%389 Q. s. JENNHNGS SWITCH MECHANISM Filed Aug.l8, 1921 g Sheets-Sheet 2 INVENTOR Oliver SJnn/ngs. BY

ATTORNEY Patented -'May 31, 1927.

- UNITED STATES PATENT OFFICE.

OLIVER S. JEN NINGS, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

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Application filed August 18, 1921. Serial No. 493,241.

My invention relates to switch mechanism and particularly to switch mechanism of the enclosed safety type.

One object of my invention is to provide a switch mechanism wherein the barrier for protecting the live terminals of the switch serves to extinguish the arc incident to the separation of the movable switch member from the switch jaw member.

Another object of my invention is to provide a barrier for protecting the live terminals of the switch and having slots therein through which the movable switch blade member of the switch passes to open or to closed position for the purpose of exposing the arc to the heat-absorbing surface immediately after the switch blade member is separated from its contact and to thereby cool and extinguish the arc.

Another object of my invention is to provide a slotted barrier, having the above characteristics, that is provided with por= tions of increasedthickness surrounding the slots for presenting an extensive heat-abaway from the blade member and, consesorbing surface in the immediate vicinity of the path of the switch blade member in order to facilitate the cooling of the arc. Another object of my invention is to provide a slotted barrier wherein the slot is enlarged at a point adjacent to the path of movement at the extreme end of the member through the slot.

Another object of my invention is to provide a slotted barrier, having the above characteristics, wherein the arc is prevented from expanding out of the slot toward the hinged jaw of the switch and thereby establishing an arc across the switch jaw members. result is accomplished by providing a slot at the point adjacent to the path of movement at the extreme end of the blade memher with an enlarged portion constituting an arc-receiving chamber and extending substantially in the pathof movement of the extreme end of the blade and directed toward the closest point of the switch jaw.

As the switch blade member separates from the switch jaw member, the arc is drawn into the chamber and, as the gases incident to the arc expand within the chamber, they are violently blown out in the path of least resistance which is toward the switch jaw member. This action blows the are This qnently, extinguishes the arc. If no ex ansion chamber were present, the are won (1 be drawn into the slot and there would be danger, under high-voltage conditions, of the are being sufficiently spread to extend to the hinged jaw and to establish an are between the switch jaw members.

A further object of my invention is to provide a switch jaw member having tapered contact jaws terminating in a point that is directly alined with the axis of the arcing chamber and at which the blade memher is separated from the switch jaw mem her. This arrangement concentrates the are at; the point of separation which is alined Wltll the arc chamber and is, therefore, readily extinguished by the blast of the gas in the chamber.

Aiurther object of my invention is to provide a switch mechanism wherein the switch blade members are confined between the barriers which separate them and prevent arcing from one to the other, and wherein the slotted barrier is so supported by the said barriers in interlocked relation therewith that it can readily be removed or replaced.

These and other objects. that will be made apparent throughout the further description of the invention, are attained by means of the switch mechanism hereinafter described, and illustrated in the accompanying draw- IIIOS, wherein:

%igure 1 is a plan view of the switch mechanism embodying features of my inventlon;

Fig. 2'is a view, partially in section and partially in elevation, of the mechanism shown in Fig. 1;

Fig. 3 is a front view of the barrier; and

Fig. 4 is a side view of the switch-separatin barrier.

Referring to the drawing, the apparatus includes a sheet metal housing 5 having a base portion 6 and side and end portions 7 and 8, respectively. The housin is rovided with a movable cover 9 that is hinged at points 11 to the side of the housing.

An insulating panel 12, which is secured to the bottom 6 of the housing, serves to support the fuse terminals 13 and, as illustrated, two pairs of switch jaw members 16 and 17. Switch blade members 18 are pivoted to the hinged jaw members 16 and in closed position,

' bar 19 that is journalled in bearin the switth jaw members engage the jaws of the jaw member 17 when such as illustrated in he switch blade members are simultaneously actuated by means of an operating 21 disthe sides 7 of the housing. The bearings 21 are axially alined with the pivots 22 of the switch blade members and the bar 19 is connected to the switch blade members by means of insulating brackets 23 that are riveted to the switch blade members. The bar 19 is provided with a handle 24 which extends exteriorly of the housing and by which the switch blade members are moved to open and to closed positions.

Each switch jaw member 17 termmates in a point 26, which is the last part of the jaw, to engage the switch blade members posed on when the blade is moved to open sition. When the blade members separate om the jaw members 17, the resultant arcing is concentrated at the oint of separation 26.

Referrin to ig. 2, it will be seen that the point X on the blade 18 is the point of separation of the blade from the point 26 of associated therewith and that this point lies beyond the switch jaw members. The point A, which becomes fused and deformed as a result of repeated arcing, lies clear of the switch jaws and in no way interferes with the contact of the jaws with the blade member.

It is an object of my invention to provide means for preventing the are from extendin from one switch blade member to the ot er and to extinguish the are as quickly as possible after the blade member has separated from its jaw member.

With this ob'ect in view, a pair of barriers 27 are dispose parallel to, and between, the switch blade members 18. The barriers are of such dimensions that the extend beyond the ends of the blade mem ers and extend outwardly a suflicient distance to separate the blade members throughout substantially their entire range of movement. The barriers are cut away at 28 in order to clear the switch-operating bar 19, which, it will be seen, is attached to the switch blade members at a point adjacent to the hinged jaw members so as to permit of a maximum area of the barriers. It will be noted that the individual blades are connected directly to the bar 19 through the members 23 without the use of a connecting bar.

The live terminals or switch jaw members 17 are rotected by means of an angularly dispose barrier 29 that is disposed transversel of the housing and which serves to prevent access to the switch jaw members 17 from the front of the housing. The barrier 29 extends over the jaw members 17 and across the ath of movement of the switch blade m m rs 18.

posite each switch blade member for the purpose of permitting the blade members to be moved to open position. The inner ends of the slots are enlarged at 32 for the urpose of providing arc-receiving cham re, the axes of which register with the points 26 of their respective switch jaw members. The barrier 29 is provided with rtions 33 of increased thickness surroun ing the slots 31 for the purpose of extendin the area of the slots through which the lilade members pass in moving to open position.

-When the switch blade member is moved to open position, the arc is formed at the gomt 26 of the switch jaw members and is awn into the arc chamber 32 by the blade 7 which serves to partially close the outer end of the chamber 32 during its passage therethrough. The gases incident to the are expand violently and are blown out of the inner end of the chamber toward the point 26 of the jaw member and blow out the arc. The are forming. in the arc chamber is rapidly cooled by the heat-absorbing surfaces of the slot 31 and the arc chamber, and it has been found that the arc is readily extin ished in the manner described before tile b ade members are moved out of the s ot.

It has been found that, if the slot 31 is not provided with an arc-receiving chamber, the pressure of the gases is sufiicient to blow the arc toward the hinged jaw members 16 and thereby establish an are between the aw members 16 and 17. The provision of t e chamber 32 eliminates this condition and serves to direct the flow of gases toward the point 26.

The barriers 27 are provided with angularly disposed slots 34 for receiving the barrier 29 which is also provided with slots 35 for receiving the barriers 27. As shown in Fig. 2, the barrier 29 is supported u n the barriers 27 by simply interlocking t e slotted portions of the barriers. By means of this arrangement, the barrier 29 may readily be removed for inspection or repair after the cover has been moved to open position. By reason of this construction, no attaching screws are necessary and the construction is simple and. inexpensive to manufacture.

While I have illustrated and described but one embodiment of my invention, it will be apparent to those skilled in the art that various changes, modifications, substitutions, additions and omissions may be made in the apparatus illustrated without departing from the spirit and scope of the invention, as set forth in the appended claims.

I claim as my invention 1. A barrier for a switch having a movable blade members comprisi an insulating plate provided with a slot ving an enlarged portion through which the end of the blade member passes in moving to closed position.

2. A barrier for a switch having a movable blade member comprising an insulating plate provided with a slot having an enlarged portion through which the blade member asses, the said barrier being of increased t ickness adjacent to the slot to provide an extensive heat-absorbing mass.

3. A barrier for a switch having a movable blade member comprising an insulating plate provided with a'slot having an enlarged portion at its inner end through which the extreme end of the blade member passes.

4. A barrier for a switch having a movable member comprising an insulating plate disposed at one side of the switch member, and a second barrier extending across the path of movement of the movable member and provided with a slot through which the movable member passes, the first barrier being provided with a slot for receiving and supporting the second barrier.

5. A barrier for aswitch having a movable member comprising an insulating plate disposed at one side of the switch member and a second barrier extending across the path of movement of the movable member and provided with a slot through which the movable member passes, the second barrier being supported by the first barrier.

6. A barrier for a switch having a movable member comprising'an insulating plate disposed at one side of the switch member and a second barrier extending across the path of movement of the movable member and provided with a slot through which the movable member passes, the second barrier being interlocked with, and supported by,

' the first barrier.

7. A switch mechanism comprising in combination a movable switch blade member, a switch contact member therefor having an end portion terminating in a point for engaging the movable blade member at a point remote from its normal contact surface and a barrier disposed across the path of movement of the blade members and provided with a slot aligned with the blade member through which the blade member passes and having an enlarged portion aligned with the said point into which the are is drawn when the blade is withdrawn from the contact member.

8. The combination with a switch blade member and a contact jaw member therefor having a means for localizing at a predetermined point, the arc incident to the separation of the members, of an arc extinguishing member having an arc chamber ,lar ed portion constituting an arc-receiving an extinguishing chamber into which the arc is drawn when the blade member is moved to open position.

10. Switch mechanism comprising a movable main current-carrying switch-blade member, and a switch-contact jaw member having the entrance edge extending at such an angle that a point on the switch-blade member that normally lies out of contact with the jaw members is the first to engage and the last to disengage a. contact point on the remote side of the jaw member, whereby the are drawn by the blade jaw members is localized on a tip of the jaw and the said point on the blade member.

11. Switch mechanism comprising a movable main current-carrying switch-blade member, aswitch-contact jaw member having the entrance edge extending at such an angle that a point on the switch-blade member that normally lies out of contact with the jaw members is the first to engage and the last to disengage a contact point on the remote side of the jaw member, whereby the are drawn by the blade jaw members is localized on a tip of the jaw and the said point on the blade member, and a barrier extending across the path of movement of the end of the blade member and provided with a slot through which the end of the blademember passes in moving to open position, the closed end of the slot being adjacent the localized are drawn between the blade member and the jaw.

'In testimony whereof. I have hereunto subscribed my name this 4th day of August,

OLIVER S. JENNINGS. 

